There has been well known a braking device (electric braking device) having an electric motor as a driving source of a servo unit for boosting a pedal effort when a brake pedal is depressed. Such an electric braking device is provided with a stroke simulator generating a pseudo-brake reaction force to the brake pedal which is depressed by a driver. For example, in Patent Document 1, there is disclosed a stroke simulator, that includes a piston to be displaced due to a hydraulic pressure generated by a depression operation of the brake pedal, and generates as the brake reaction force a reaction force occurring in a first spring and a second spring which are elastically deformed by a depression force due to a displacement of the piston.